[mkgmap-dev] [PATCH v1] garmin_area() style function

Sat Aug 10 12:21:07 BST 2013

> I think it wouold be better to have a conversion in the documentation.

Good idea.
I have calculated some examples, how many m^2 are one garmin_unit^2.
The conversion is dependent on the latitude value only (is this correct?):

1 garmin_unit^2 is:
Latitude   m^2
====================
-85°  0,79 m^2
-80°  0,81 m^2
-75°  1,63 m^2
-70°  1,83 m^2
-65°  2,43 m^2
-60°  2,82 m^2
-55°  3,20 m^2
-50°  3,66 m^2
-45°  4,00 m^2
-40°  4,33 m^2
-35°  4,64 m^2
-30°  4,87 m^2
-25°  5,15 m^2
-20°  5,35 m^2
-15°  5,47 m^2
-10°  5,60 m^2
  -5°  5,66 m^2
   0°  5,71 m^2
   5°  5,68 m^2
  10°  5,61 m^2
  15°  5,52 m^2
  20°  5,35 m^2
  25°  5,17 m^2
  30°  4,93 m^2
  35°  4,66 m^2
  40°  4,36 m^2
  45°  4,03 m^2
  50°  3,66 m^2
  55°  3,26 m^2
  60°  2,85 m^2
  65°  2,41 m^2
  70°  1,95 m^2
  75°  1,47 m^2
  80°  0,99 m^2
  85°  0,50 m^2

Having a look at the results I guess the procedure to calculate the area 
size in m^2 is wrong. I think results for lat=x° should equal lat=-x°?

WanMil